package com.question.aspect;

import com.question.annotation.AutoFill;
import com.question.constant.AutoFillConstant;
import com.question.context.BaseContext;
import com.question.enumeration.OperationType;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.time.LocalDateTime;

/**
 * 自定义切面，实现公共字段自动填充逻辑
 */
@Aspect
@Component
@Slf4j
public class AutoFillAspect {

    /**
     * 切入点
     */
    @Pointcut("execution( * com.question.mapper.*.*(..)) && @annotation(com.question.annotation.AutoFill)")
    public void autoFillPointCut() {
    }

    /**
     * 前置通知，在通知中进行公共字段的赋值
     */
    @Before("autoFillPointCut()")
    public void autoFill(JoinPoint joinPoint){
        log.info("开始进行公共字段自动填充...");

        //获取当前拦截方法上的数据库操作类型
        MethodSignature signature = (MethodSignature)joinPoint.getSignature();   //方法签名对象
        AutoFill autoFill = signature.getMethod().getAnnotation(AutoFill.class);   //获取方法上的注解对象
        OperationType operationType = autoFill.value();   //获取数据库操作类型

        //获取当前被拦截方法的参数--实体对象
        Object[] args = joinPoint.getArgs();
        if (args == null || args.length == 0){
            return;
        }

        Object entity = args[0];

        //赋值数据
        LocalDateTime now = LocalDateTime.now();
        Long currentId = BaseContext.getCurrentId();

        //根据数据库操作类型，为对应实体对象的属性通过反射赋值
        if (operationType == OperationType.CREATED_AT){
            try {
                Method setCreateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATED_AT, LocalDateTime.class);

                //通过反射为实体对象属性赋值
                setCreateTime.invoke(entity, now);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else if(operationType == OperationType.SUBMITTED_AT){
            try {
                Method setSubmitTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_SUBMITTED_AT, LocalDateTime.class);

                //通过反射为实体对象属性赋值
                setSubmitTime.invoke(entity, now);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else if(operationType == OperationType.CREATED_AT_BY){
            try {
                Method setCreateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATED_AT, LocalDateTime.class);
                Method setCreateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATED_BY, Long.class);

                //通过反射为实体对象属性赋值
                setCreateTime.invoke(entity, now);
                setCreateUser.invoke(entity, currentId);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }

    }

}
